Bug 398928, allow dragging window on Mac by the toolbar, r=neil,sr=roc,a=beltzner

browser/base/content/browser.xul

@@ -237,7 +237,7 @@
     </vbox>
   </tooltip>
 
-  <toolbox id="navigator-toolbox" class="toolbox-top" mode="icons"
+  <toolbox id="navigator-toolbox" type="drag" class="toolbox-top" mode="icons"
            defaultmode="icons">
     <!-- Menu -->
     <toolbar type="menubar" id="toolbar-menubar" class="chromeclass-menubar" customizable="true"

content/base/src/nsGkAtomList.h

@@ -850,6 +850,9 @@ GK_ATOM(tokenize, "tokenize")
 GK_ATOM(toolbar, "toolbar")
 GK_ATOM(toolbarbutton, "toolbarbutton")
 GK_ATOM(toolbaritem, "toolbaritem")
+GK_ATOM(toolbarseparator, "toolbarseparator")
+GK_ATOM(toolbarspacer, "toolbarspacer")
+GK_ATOM(toolbarspring, "toolbarspring")
 GK_ATOM(toolbox, "toolbox")
 GK_ATOM(tooltip, "tooltip")
 GK_ATOM(tooltiptext, "tooltiptext")

layout/xul/base/src/nsTitleBarFrame.cpp

@@ -84,6 +84,83 @@ nsTitleBarFrame::Init(nsIContent*      aContent,
   return rv;
 }
 
+class nsDisplayTitleBarRedirector : public nsDisplayWrapList {
+public:
+  nsDisplayTitleBarRedirector(nsIFrame* aFrame, nsDisplayItem* aItem,
+                              nsIFrame* aTargetFrame)
+    : nsDisplayWrapList(aFrame, aItem), mTargetFrame(aTargetFrame) {}
+  nsDisplayTitleBarRedirector(nsIFrame* aFrame, nsDisplayList* aList,
+                              nsIFrame* aTargetFrame)
+    : nsDisplayWrapList(aFrame, aList), mTargetFrame(aTargetFrame) {}
+  virtual nsIFrame* HitTest(nsDisplayListBuilder* aBuilder, nsPoint aPt,
+                            HitTestState* aState);
+  NS_DISPLAY_DECL_NAME("XULTitleBarRedirector")
+private:
+  nsIFrame* mTargetFrame;
+};
+
+nsIFrame* nsDisplayTitleBarRedirector::HitTest(nsDisplayListBuilder* aBuilder,
+                                               nsPoint aPt, HitTestState* aState)
+{
+  nsIFrame* frame = mList.HitTest(aBuilder, aPt, aState);
+  if (!frame)
+    return nsnull;
+
+  // We want a drag over a background-like child of the titlebar to move the
+  // window, which means that the event must be retargetted at the titlebar.
+  // However, other elements such as controls should receive events normally.
+  // Here, we look for tags that usually represent empty space. A loop that
+  // iterates up the parent chain is used so that these elements can still
+  // appear inside a non-background element, for instance an hbox that is
+  // inside a button should still be targetted as normal.
+  nsIFrame* foundframe = frame;
+  while (foundframe && foundframe != mTargetFrame) {
+    nsIContent* content = foundframe->GetContent();
+    if (content) {
+      // not a XUL element so target normally
+      if (content->GetNameSpaceID() != kNameSpaceID_XUL)
+        return frame;
+
+      nsIAtom* tag = content->Tag();
+      // if this is not a background-like element, use the original frame that
+      // was targetted, so that the event is processed as normal
+      if (tag != nsGkAtoms::box &&
+          tag != nsGkAtoms::hbox &&
+          tag != nsGkAtoms::vbox &&
+          tag != nsGkAtoms::spacer &&
+          tag != nsGkAtoms::toolbar &&
+          tag != nsGkAtoms::toolbaritem &&
+          tag != nsGkAtoms::toolbarspacer &&
+          tag != nsGkAtoms::toolbarspring &&
+          tag != nsGkAtoms::toolbarseparator)
+            return frame;
+    }
+
+    foundframe = foundframe->GetParent();
+  }
+
+  // retarget to the titlebar
+  return mTargetFrame;
+}
+
+class nsXULTitleBarWrapper : public nsDisplayWrapper
+{
+public:
+  nsXULTitleBarWrapper(nsIFrame* aTargetFrame)
+      : mTargetFrame(aTargetFrame) {}
+  virtual nsDisplayItem* WrapList(nsDisplayListBuilder* aBuilder,
+                                  nsIFrame* aFrame, nsDisplayList* aList) {
+    return new (aBuilder) nsDisplayTitleBarRedirector(aFrame, aList, mTargetFrame);
+  }
+  virtual nsDisplayItem* WrapItem(nsDisplayListBuilder* aBuilder,
+                                  nsDisplayItem* aItem) {
+    return new (aBuilder) nsDisplayTitleBarRedirector(aItem->GetUnderlyingFrame(),
+                                                      aItem, mTargetFrame);
+  }
+private:
+  nsIFrame* mTargetFrame;
+};
+
 NS_IMETHODIMP
 nsTitleBarFrame::BuildDisplayListForChildren(nsDisplayListBuilder*   aBuilder,
                                              const nsRect&           aDirtyRect,
@@ -91,9 +168,17 @@ nsTitleBarFrame::BuildDisplayListForChildren(nsDisplayListBuilder*   aBuilder,
 {
   // override, since we don't want children to get events
   if (aBuilder->IsForEventDelivery()) {
-    if (!mContent->AttrValueIs(kNameSpaceID_None, nsGkAtoms::allowevents,
+    if (mTrackingMouseMove ||
+        !mContent->AttrValueIs(kNameSpaceID_None, nsGkAtoms::allowevents,
                                nsGkAtoms::_true, eCaseMatters))
       return NS_OK;
+
+   nsDisplayListCollection set;
+   nsresult rv = nsBoxFrame::BuildDisplayListForChildren(aBuilder, aDirtyRect, set);
+   NS_ENSURE_SUCCESS(rv, rv);
+
+   nsXULTitleBarWrapper wrapper(this);
+   return wrapper.WrapLists(aBuilder, this, set, aLists);
   }
   return nsBoxFrame::BuildDisplayListForChildren(aBuilder, aDirtyRect, aLists);
 }

toolkit/content/widgets/toolbar.xml

@@ -69,6 +69,13 @@
     </implementation>
   </binding>
   
+  <binding id="toolbox-drag" display="xul:titlebar"
+           extends="chrome://global/content/bindings/toolbar.xml#toolbox">
+    <content allowevents="true">
+      <children/>
+    </content>
+  </binding>
+
   <binding id="toolbar" extends="chrome://global/content/bindings/toolbar.xml#toolbar-base">
     <implementation implements="nsIAccessibleProvider">
       <property name="accessibleType" readonly="true">

toolkit/content/xul.css

@@ -219,6 +219,12 @@ toolbox {
   -moz-box-orient: vertical;
 }
 
+%ifdef XP_MACOSX
+toolbox[type="drag"] { 
+  -moz-binding: url("chrome://global/content/bindings/toolbar.xml#toolbox-drag");
+}
+%endif
+  
 toolbar {
   -moz-binding: url("chrome://global/content/bindings/toolbar.xml#toolbar");
 }